Insecticidal esters of 1-acenaphthenol

ABSTRACT

1. A COMPOUND OF THE FORMULA   R-COO-R&#39;&#39;   WHEREIN R IS A CYCLOPROPANE MOIETY SELECTED FROM THE GROUP CONSISTING OF   2,2,3,3-TETRA(H3C-)-CYCLOPROPYL-, 2,2-DI(H3C-),3-((H3C)2-   C=CH-)-CYCLOPROPYL-, AND 2,2-DI(H3C-),3-((-(CH2)N-)&gt;C=   CH-)-CYCLOPROPYL-   WHEREIN N IS AN INTEGER OF FROM 4 TO 6 AND WHEREIN R&#39;&#39; IS A 1-ACEBNAPHTHENYL OR TEYRAHYDRO-1-ACENAPHTHENYL MOIETY OF THE FORMULA   X1,X2-ACENAPTHENE OR X1,X2-2A,3,4,5-TETRAHYDROACENAPTHENE   WHEREIN X1 AND X2 ARE EACH SELECTED FROM THE GROUP CONSISTING OF HYDROGEN, HALOGEN, NITRO, THIOMETHYL, STRAIGHT OR BRANCHED CHAIN ALKYL CONTAINING FROM ABOUT 1 TO 5 CARBON ATOMS, ALKOXY CONTAINING FROM ABOUT 1 TO 2 CARBON ATOMS AND SULFONYLMETHYL.

nit-ed States Patent O 3,840,584 INSECTICIDAL ESTERS F l-ACENAPHTHENOL Robert J. Crawford, Wyoming, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio No Drawing. Filed Nov. 12, 1971, Ser. No. 198,434 Int. Cl. C07c 69/74 U.S. Cl. 260-468 H 13 Claims ABSTRACT OF THE DISCLOSURE Cyclopropanecarboxylic acid esters of l-acenaphthenol and substituted l-acenaphthenols possessing useful insecticidal properties.

BACKGROUND OF THE INVENTION This invention relates to novel cyclopropanecarboxylic acid esters of l-acenaphthenol, and derivatives thereof, as well as insecticidal compositions containing said esters as an essential active ingredient.

Current trends in the chemical control of insects call for inherently safer materials which degrade very rapidly to non-toxic substances once their purpose is accomplished. The safety of the widely used chlorinated hydrocarbons, notably DDT, is currently under question largely because of their poor biodegradability and concomitant persistence. Accordingly, there is a great demand for alternative broad spectrum insecticides which are suitable for the high volume usage entailed in agricultural applications. At the same time it is desirable for new insecticides to exhibit a low order of toxicity to warm-blooded animals. Of the several insecticidal classes which demonstrate low mammalian toxicity and good biodegradability, it has long been recognized that pyrethrum, a naturally-occurring insecticidal mixture, possesses these desirable properties. In addition to the safety advantages, this natural mixture causes rapid knock-down and kill of a broad spectrum of insects; however, it is unstable to light, air, and heat, and is very expensive. The most active component of pyrethrum is pyrethrin I and a number of analogous compounds have been proposed for insecticidal use. Allethrin, a typical synthetic pyrethrin-like insecticide, while more stable to light and heat than pyrethrum, is nevertheless expensive, a defect which is compounded by the fact that this substance is not appreciably synergized by the low cost synergizing agents such as piperonyl butoxide which are typically used in insecticidal compositions. Because of instability, high cost and limited supply, the use of pyrethrum and pyrethrinlike insecticides in agricultural applications has been precluded or seriously limited.

At the same time, it is well known that certain insects, in time, become immune to the insecticidal properties of various chemical agents. To be efficient, an insecticide should be able to resist detoxification by the insect. While biological mechanisms whereby insects are capable of de toxifying the various types of insecticidal compounds are not fully understood, it is possible that, as with other biological systems, insects may in time develop new biochemical processes capable of detoxifying any particular insecticidal compound. In any event, it is desirable to have included in the insecticidal armamentarium compounds which can be utilized once a given class of insects is found no longer to respond to conventional insecticidal compounds.

Many prior art insecticidal esters differ from one another and from the natural pyrethrin I esters by virtue of synthetic modifications in the alcohol moiety of the ester. Other synthetic insecticides are pyrethrin-like esters modified in the acid portion of the ester molecule. For example, the copending application of Fanta, entitled Inice secticidal Esters, Ser. No. 208,040, filed Dec. 9, 1971; U.S. Pat. 3,679,667, July 25, 1972, to W. Fanta; U.S. Pat. 3,465,007, Sept. 2, 1969, to M. Elliott, all relate to various synthetic insecticidal esters of the pyrethrum type. However, a major shortcoming of the prior art synthetic pyrethrin I analogues is their cost, and it is of major interest to provide a class of such analogues which is moderately priced. To achieve this, it is necessary to provide a moderately priced alcohol which, when esterified with an appropriate cyclopropanecarboxylic acid, forms an insecticidal ester. It has now been discovered that l-acenaphthenol, and the various derivatives thereof, can be used in conjunction with cyclopropanecarboxylic acids to provide insecticidal esters of the pyrethrum type at moderate cost.

It is therefore an object of this invention to provide novel insecticidal l-acenaphthenol esters of cyclopropanecarboxylic acids which are biodegradable, efiect rapid knock-down and kill of a broad spectrum of insects, possess low mammalian toxicity and are less susceptible to detoxification by insects than is pyrethrum. This and other objects are obtained by the present invention as will become apparent from the following disclosure.

SUMMARY OF THE INVENTION DETAILED DESCRIPTION OF THE INVENTION The cyclopropanecarboxylic acid esters of l-acenaphthenol, tetrahydro-l-acenaphthenols and the derivatives thereof are of the formula R l-0R' wherein R is a cyclopropane moiety selected from the group consisting of wherein n is an integer of from 4 to 6, preferably 4, and wherein R is a l-acenaphthenyl or tetrahydro-lacenaphthenyl moiety of the formula 8 3 or 8 3 X1 l X2 X1 I X2 7 4 7\/ 4 6 5 5 wherein X and X are each selected from the group consisting of hydrogen, halogen, nitro, thiomethyl, alkyl, (e.g., ethyl, methyl, propyl, butyl, neopentyl, isopropyl), alkoxyl, (e.g., methoxyl, ethoxyl) sulfonylmethyl and the 3 like. The substituents X and X can be at any one or more of the positions marked 3, 4, 5, 6, 7 and 8 on the above-indicated ring structures. The esterification is at the 1-position on the acenaphthenol or tetrahydro-1- acenaphthenol ring system.

The insecticidal compounds of this invention are prepared by esterifying l-acenaphthenol, tetrahydro-1- acenaphthenol, and substituted derivatives thereof, with cyclopropanecarboxylic acids or acid halides in the manner hereinafter detailed. l-Acenaphthenol is prepared by the oxidation of acenaphthene, an abundant constitutent of coal tar (see L. Fieser and I. Cason, J. Amer. Chem. Soc., 62, 432, 1940). Substituted acenaphthenes suitable for use in the preparation of the substituted l-acenaphthenols useful in this invention can be prepared using standard synthetic procedures. The substituted acenaphthenes can be oxidized to the corresponding substituted l-acenaphthenols using the procedure of Fieser and Cason, above, and the resulting substituted l-acenaphthenols then used to prepare the corresponding cyclopropanecarboxylic acid esters. The following exemplary substituted acenaphthene compounds, any of which can be converted to the corresponding substituted l-acenaphthenols useful herein, have been reported, along with others, in Chemical Abstracts, vols. 1-72, 3-chloroacenaphthene, chloroacenaphthene, 3,6-dichloroacenaphthene, 5,6-dichloroacenaphthene, 5-bromoacenaphthene, 3-fluoroacenaphthene, 4-fluoroacenaphthene, 5- ifiuoro-6-nitroacenaphthene, B-iodoacenaphthene, 3-thiomethylacenaphthene, 3 -nitroacenaphthene, 5-nitroacenaphthene, 3,4-dinitroacenaphthene, 4-ethylacenaphthene, 4-methylacenaphthene, 4-t-butylacenaphthene, 3-isopropylacenaphthene, 3,8-dimethylacenaphthene, S-methoxyacenaphthene, 5-methoxy-4-nitroacenaphthene, 3,7-di-tbutylacenaphthene, S-propenylacenaphthene.

2a,3,4,5-Tetrahydro-1-acenaphthenol (and substituted derivatives thereof) can be prepared by the general procedure of Richter and Silver, J. Org. Chem. 33, 3283 (1968). Alternatively, these compounds (referred to herein simply as "tetrahydro-l-acenaphthenols) can be prepared by partially hydrogenating the corresponding 1- acenaphthenols, such as those disclosed above, using well-known procedures (e.g., Pd/C hydrogenation).

The following l-acenaphthenol and tetrahydro-1- acenaphthenols are preferred for use in the preparation of the compounds of this invention by virtue of their low cost, ease of preparation and the high insecticidal activity of the cyclopropanecarboxylic esters which they form: l-acenaphthenol, 6-chloro-1-acenaphthenol, 5- nitro-l-acenaphthenol, 5,6-dichloro-l-acenaphthenol, 5- methoxy-l-acenaphthenol, tetrahydro 1 acenaphthenol and 6-chloro-tetrahydro-l-acenaphthenol.

The cyclopropane carboxylic acids used to prepare the insecticidal esters of the instant invention can be prepared by standard procedures disclosed in the art. The copending application of Fanta, Ser. No. 23,513, above, describes the preparation of 3-(2,2-tetrarnethylene ethenyl)-2,2-dimethylcyclopropanecarboxylic acid; chrysanthemoyl chloride can be prepared in the manner of Crombie, et al., J. Chem. Soc. 3552 (1950); 2,2,3,3-tetramethylcyclopropanecarboxylic acid can be prepared in the manner of Matsui and Kitahara, Agr. Biol. Chem. (Tokyo) 31, 1143 (1967) and converted to the acid chloride using thionyl chloride.

The following gross synthetic scheme outlines the preparation of the insecticidal esters of this invention:

Acetic Acid then wherein R, X and X are as disclosed above.

According to the above outline, the esters of this invention are prepared by a step-wise process comprising: (1) preparing the l-acenaphthenol, tetrahydro-l-acenaphthenol, or derivatives thereof according to the procedures described in the foregoing references; (2) esterifying the alcohol with a stoichiometric amount of a cyclopropanecar-boxylic acid chloride which is also prepared by standard procedures (above).

Alternatively, the esterification step of the present invention can be effected in other ways. The l-acenaphthenol, tetrahydro 1 acenaphthenol, or derivatives thereof as disclosed above, can be heated with the appropriate cyclopropanecarboxylic acid in the presence of a strong acid (e.g., H H010 etc.) in an organic solvent capable of azeotropically boiling with water, thereby removing the water formed in the esterification. The l-acenaphthenol or tetrahydro-I-acenaphthenol compound can also be heated with a lower alkyl ester of a cyclopropanecarboxylic acid in the presence of a basic catalyst such as sodium hydroxide, potassium hydroxide, sodium alcoholate, or potassium alcoholate, and the like, while continuously removing the lower alcohol formed through transesterification of the reaction system. In such cases, the methyl, ethyl, n-propyl and iso-propyl esters of the cyclopropanecarboxylic acids are suitable. In the most preferable esterification, the l-acenaphthenol, tetrahydro l-acenaphthenol, or derivatives thereof, is allowed to react with a cyclopropanecarboxylic acid halide, preferably at temperatures from about 20 C. to about C., in an inert solvent, preferably in the presence of an agent such as pyridine, triethylamine or other suitable amine, such that the esterification proceeds with the formation of a hydrohalic acid salt within a short period of time. For this purpose, the cyclopropanecarboxylic acid chloride is the most preferred, although the acid bromide and the acid iodide can be employed.

The compounds of this invention can exist in several isomeric and optically isomeric forms, e.g., cis-configuration, trans-configuration, dextroand levorotatory forms of each, etc., and mixtures and racemates thereof. It is intended that the claims herein be construed to encompass all such forms and mixtures thereof. Preferred insecticidal esters herein are l-acenaphthenol chrysanthemate, 6- chloro 1 acenaphthenol chrysanthemate, 5 nitro1- acenaphthenol chrysanthemate, tetrahydro 1 acenaphthenol cthrysanthemate, 1 acenaphthenol 2,2,3,3 tetramethylcyclopropanecarboxylate, 6-chloro 1 acenaphthenol 2,2,3,3 tetramethylcyclopropanecarboxylate, 5- nitro 1 acenaphthenol 2,2,3,3-tetramethylcyclopropanecarboxylate, tetrahydro 1 acenaphthenol 2,2,3,3 tetramethylcyclopropaneca-rboxylate, 1 acenaphthenol 3-(2,2- tetramethylene ethenyl) 2,2 dimethylcyclopropanecarboxylate, 6 chloro 1 acenaphthenol 3-(2,2-tetramethylene ethenyl) 2,2 dimethylcyclopropanecarboxylate, 5 nitro 1 acenaphthenol 3 (2,2 tetramethylene ethenyl)-2,2-dimethylcyclopropanecarboxylate, and tetrahydro 1 acenaphthenol 3 (2,2 tetramethylene ethenyl) -2,Z-dimethylcyclopropanecarboxylate.

The preparation of the esters of the present invention is described in more detail in the following examples. The inert organic solvents used in the procedures are those which do not react with the l-acenaphthenol or tetrahydro-l-acenaphthenol compound or with the cyclopropanecarboxylic acids or acid halides. Such solvents are preferably aprotic solvents such as hexane, benzene, acetone, ether, glyme, and the like. The examples are not intended to be limiting, but only to demonstrate the preparation of a variety of compounds of this invention.

EXAMPLE I l-Acenaphthenol chrysanthemate To an ice-cold, stirred solution of 14.00 g. of *)chrysanthemoyl chloride (cis-trans-isomer mixture) in 100 ml. of anhydrous benzene, under static argon atmosphere, was added dropwise 12.1 ml. of dry pyridine. The resulting mixture was cooled to 5 C., and 11.90 g. of solid l-acenaphthenol, prepared in the manner of Fieser and Cason, above, was added to the benzene solution in small portions. This mixture was stirred for 2 hours at C., 20 hours at room temperature, and then was poured into 500 ml. of diethyl ether. The ether solution was washed with 100 ml of 3M HCl, two 100 ml. portions of 5% aqueous sodium carbonate, 100 ml. of saturated sodium chloride solution, and dried over anhydrous magnesium sulfate. The ether was removed at reduced pressure on a rotary evaporator. The residue was vacuum dried (25 C., 0.02 mm.) and afforded 22.99 g. of (i) cis-trans-l-acenaphthenol chrysanthemate whose structure was verified by spectral measurements.

In the above procedure, the l-acenaphthenol is replaced by an equivalent amount of the following substituted acenaphthenols, respectively:

5-chlorol-acenaphthenol, 6-chloro-l-acenaphthenol, 6-bromo-1-acenaphthenol, 6-fluoro-1-acenaphthenol, 6-iodo-1-acenaphthenol, 5-nitro-1-acenaphthenol, B-nitro-l-acenaphthenol, 5,6-dichlorol-acenaphthenol, 5 -methoxyl-acenaphthenol, 5-thiomethyl-l-acenaphthenol, 5-sulfonylmethyll-acenaphthenol, tetrahydrol-acenaphthenol, 3-ethyl-1-acenaphthenol;

the corresponding substituted l-acenaphthenol and tetrahyro-l-acenaphthenol chrysanthemates are secured.

Using the apparatus and procedures of Example I, above, 3-(2,2-tetramethylene ethenyl) 2,2 dimethylcyclopropanecarboxylic acid chloride and 2,2,3,3 tetramethylcyclopropanecarboxylic acid chloride, respectively are reacted with the following alcohols: l-acenaphthenol, 6- chloro-l-acenaphthenol, S-nitro-l-acenaphthenol, and tetrahydro-l-acenaphthenol and the following esters are secured:

l-acenaphthenol 3-(2,2-tetramethylene ethenyl)-2,2-

dimethylcyclopropanecarboxylate,

6-chloro-l-acenaphthenol 3-(2,2-tetramethylene ethenyl)- 2,Z-dimethylcyclopropanecarboxylate,

S-nitro-l-acenaphthenol 3-(2,2-tetramethylene ethenyl)- 2,2-dimethylcyclopropanecarboxylate,

tetrahydro-l-acenaphthenol 3-(2,2-tetramethylene ethenylcyclopropanecarboxylate,

l-acenaphthenol 2,2,3,3-tetramethylcyclopropanecarboxylate,

6-chloro-1-acenaphthenol 2,2,3,3-tetramethylcyclopropanecarboxylate,

S-nitro-l-acenaphthenol 2,2,3,3-tetramethylcyclopropanecarboxylate and tetrahydro-l-acenaphthenol 2,2,3,3-tetramethylcyclopropanecarboxylate.

The following test is intended to illustrate the insecticidal properties of a representative ester herein, but is not intended to limit the scope of the invention.

Insecticidal evaluation An insecticidal composition comprising the ester of cis-trans-l-acenaphthenol chrysanthemate from Example I, dissolved in acetone and dispersed in distilled water with Triton X-* emulsifier was prepared. The composition was applied for a ten second period to houseflies retained in a 2 x 5 diameter screened cage. The spray was applied from a Waters vertical spray tower operating at 10 psi. and discharging about 30 ml. of material per minute through an atomizer. The spray descends through an 8" stainless steel cylinder to test insects below the atomizer. The insects were retained in the sprayed cages for mortality observations. Test compositions having the indicated percentage concentration of weight (W) of test compound to spray volume (V) were utilized in the tests. The results are set forth in Table 1 below.

TABLE 1.HOUSEFLY TESTS-KNOCK-DOWN AND KILL Average percent;

Knock- Percent down Mortality Ester WW (2 hours) (24 hours) l-acenaphthenol chrysanthemate 0. 1 100 100 Do 0. 05 96 70 Do 0. 01 4 56 As can be seen from the foregoing data, a representative compound of this invention possesses excellent insecticidal properties. Additionally, the compounds of the in stant invention are substantially less toxic to mammals than are most common insecticides.

Similar results are secured when S-chloro-l-acenaphthenol chrysanthemate, 6-chloro-1-acenaphthenol chrysanthemate, 5,6-dichloro-l-acenaphthenol chrysanthemate, S-methoxy-l-acenaphthenol chrysanthemate, 6-chloro-tetrahydro-l-acenaphthenol chrysanthemate, 7-ethyl-tetrahydro-l-acenaphthenol chrysanthemate, and S-nitro-l-acenaphthenol chrysanthemate,

respectively, are incorporated in the insecticidal composition in place of the l-acenaphthenol chrysanthemate in the above test.

Using the general procedure described above, isomer mixtures of respectively, are applied to houseflies, the Southern army worm, the Mexican bean beetle, the pea aphid, the adult mosquito, adult stable fiies, black carpet beetle larva, web- *Isooctyl phenyl polyethoxy OPE 9-10 supplied by Rohm & Haas Company.

bing clothe moth larva, adult rice weevils, and adult sawtooth grain beetles and these insects are controlled. As can be seen, the compounds herein are effective against a wide variety of insects.

Insecticidal compositions containing the esters of the present invention can be formulated and utilized as oil solutions, emulsifiable concentrates, wettable powders, dusts, aerosols, or impregnated into wood, fabrics, etc., and provide a long lasting residual effect. Such comopsitions can include the generally employed carriers or diluents and auxiliary agents which are well-known to those skilled in the art. For example, suitable dusts can be prepared by admixing the compounds of the invention with dry free-flowing powders such as clay, bentonite, fullers earth, diatomaceous earth, pyrophyllite, attapulgite, calcium carbonate, chalk or the like. The active compounds of the invention normally comprise up to about 10% by weight of such dust formulations. An amount of up to about 3% is preferred and is suitable for most applications.

Likewise, suspensions or dispersions of the compounds in a non-solvent, such as water, can be suitably employed for the treatment of foliage. Also suitably employed are solutions of the insecticides of this invention in oil which is emulsified in water. Examples of oil solvents include hydrocarbons such as benzene and toluene, halogenated hydrocarbons such as chlorobenzene, chloroform, fluorotrichloromethane and dichloro-difluoromethane, and commercial mixtures of hydrocarbons such as the common Stoddard solvent, petroleum ethers, and the like.

Aerosols can be prepared by dissolving the compounds of the invention in a highly volatile liquid carrier such as trifluorochloromethane, nitromethane, dichlorodifluoroethane and the like, or by dissolving such compounds in a less volatile solvent, such as benzene or kerosene, and admixing the resulting solution with a highly volatile liquid aerosol carrier such as the polyfluorohydrocarbons commonly used as aerosol propellants.

The insecticidal esters of this invention are useful for destroying a variety of insects. Accordingly, a method aspect of the present invention comprises combating insects by applying to said insects, or to an insect habitat, one or more of novel compounds disclosed herein.

Preferably the esters of this invention are employed in combination with a synergistic agent, for example, piperonyl butoxide, piperonyl sulfoxide, ,8-butoxy-/8'-thiocyanodiethyl ether and the like.

What is claimed is:

1. A compound of the formula ll RCOR wherein R is a cyclopropane moiety selected from the group consisting of 8 wherein n is an integer of from 4 to 6 and wherein R is a l-acenaphthenyl or tetrahydro-l-acenaphthenyl moiety of the formula wherein X, and X are each selected from the group consisting of hydrogen, halogen, nitro, thiomethyl, straight or branched chain alkyl containing from about 1 to 5 carbon atoms, alkoxyl containing from about 1 to 2 carbon atoms and sulfonylmethyl.

2. A compound according to Claim 1 which is l-acenaphthenol crysanthemate.

3. A compound according to Claim 1 which is 6-chlorol-acenaphthenol chrysanthemate.

4. A compound according to Claim 1 which is S-nitrol-acenaphthenol chrysanthemate.

5. A compound according to Claim 1 which is tetrahydro-l-acenaphthenol chrysanthemate.

6. A compound according to Claim 1 which is 1-ace naphthenol 2,2,3,3-tetramethylcyelopropanecarboxylate.

7. A compound according to Claim 1 which is 6-chlorol-acenaphthenol 2,2,3,3 tetramethylcyclopropanecarboxylate.

8. A compound according to Claim 1 which is S-nitrol-acenaphthenol 2,2,3,3 tetramethylcyclopropanecarboxylate.

9. A compound according to Claim 1 which is tetrahydro-l-acenaphthenol 2,2,3,3 tetramethylcyclopropanecarboxylate.

10. A compound according to Claim 1 which is l-acenaphthenol 3 (2,2-tetramethylene ethenyl)-2,2-dimethylcyclopropanecarboxylate.

11. A compound according to Claim 1 which is 6- chloro 1 acenaphthenol 3-(2,2-tetramethylene ethenyl)- 2,Z-dimethylcyclopropanecarboxylate.

12. A compound according to Claim 1 which is 5-nitrol-acenaphthenol 3-(2,2-tetramethylene ethenyl) 2,2-dimethylcyclopropanecarboxylate.

13. A compound according to Claim 1 which is tetrahydro-l-acenaphthenol 3 (2,2 tetramethylene ethenyl)- 2,2-dimethylcyclopropanecarboxylate.

References Cited UNITED STATES PATENTS 3,647,857 3/1972 Morgan 260468 ROB'ERT GERSTL, Primary Examiner US. Cl. X.R. 

1. A COMPOUND OF THE FORMULA 